<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
       let obj = {
        name: "张三",
        age : '李四'
       }

    //    let xin = {...obj}
    let xin = obj
    xin = {}
    xin.name = "李四"
    console.log(obj);

    // let add = function () {
    //     console.log(arguments);
    // }
    // arr = [10,20,30,40]
    // let add = function (...a) {
    //     console.log(a);
    //     console.log(arguments);
    // }
    // 没有传，默认给[],...a必须写到最后
    let add = function (a,b,...c) {
        console.log(c);
        console.log(arguments);
    }
    add(10,20,30)
    </script>
</body>
</html>